Eye tracking module and head-wearable device

Abstract

An eye tracking module for a head-wearable device of a user includes an electronics carrier, an image sensor arranged on the electronics carrier, an optical path for receiving visible light at the image sensor from a first region of interest, and an IR-waveguide arranged with respect to the optical path such that received visible light is at least substantially not diverted and/or guided by the IR-waveguide. The IR-waveguide includes a first input aperture for receiving IR-light from a second region of interest which is different to the first region of interest, and an output aperture for outputting at least a part of the received IR-light towards the image sensor.

The invention claimed is: 
     
         1 . An eye tracking module for complementing a head-wearable device of a user, the eye tracking module comprising:
 an electronics carrier;   an image sensor arranged on the electronics carrier;   a straight optical path for receiving visible light at the image sensor from a first region of interest; and   an IR-waveguide arranged with respect to the optical path to avoid received visible light from being diverted and/or guided by the IR-waveguide, the IR-waveguide comprising a first input aperture for receiving IR-light from a second region of interest which is different to the first region of interest, and an output aperture for outputting at least a part of the received IR-light towards the image sensor, wherein the IR-waveguide is a one-piece structure, wherein the IR-waveguide comprises, in a direction at least substantially parallel to the optical path and/or an optical axis of the image sensor, and/or at least substantially perpendicular to an image plane of the image sensor, a thickness of at most about 2 mm, wherein the IR-waveguide is, in a projection onto a projection plane at least substantially perpendicular to the optical path and/or the optical axis, and/or onto to the image plane of the image sensor, U-shaped, and/or wherein the IR-waveguide or even the eye tracking module is mirror symmetric with respect to a symmetry plane parallel to the optical path and/or the optical axis.   
     
     
         2 . The eye tracking module of  claim 1 , wherein the IR-waveguide is arranged in the optical path, wherein visible light received via the optical path traverses the IR-waveguide, wherein the IR-waveguide is configured for not guiding visible light and/or wherein the IR-waveguide is at least substantially transparent for the visible light, at least in a portion that is arranged in the optical path. 
     
     
         3 . The eye tracking module of  claim 1 , wherein no prism is arranged between the output aperture and the image sensor. 
     
     
         4 . The eye tracking module of  claim 1 , wherein no optical element is arranged between the output aperture and the image sensor. 
     
     
         5 . The eye tracking module of  claim 1 , wherein the IR-waveguide comprises a carrier or substrate and a thin polymeric film arranged on the carrier or substrate. 
     
     
         6 . The eye tracking module of  claim 1 , wherein the IR-waveguide comprises a second input aperture for receiving IR-light from a third region of interest. 
     
     
         7 . The eye tracking module of  claim 6 , wherein the IR-waveguide is configured to guide IR-light from the first input aperture to the output aperture, and from the second input aperture to the output aperture. 
     
     
         8 . The eye tracking module of  claim 1 , further comprising an IR-light source arranged on the electronics carrier, wherein the output aperture is configured to receive illumination light from the IR-light source. 
     
     
         9 . The eye tracking module of  claim 1 , wherein the first input aperture is arranged in a first leg portion of the IR-waveguide, wherein the second input aperture is arranged in a second leg portion of the IR-waveguide, wherein the first region of interest corresponds to a scene in front of the user wearing the head-wearable device, wherein the first region of interest is related to a field of view of the user wearing the head-wearable device, wherein the second region of interest is related to a first eye of the user wearing the head-wearable device, and/or wherein the third region of interest is related to a second eye of the user wearing the head-wearable device. 
     
     
         10 . The eye tracking module of  claim 1 , wherein the image sensor comprises at least one of: an array sensor, and a filter arranged on the array sensor, in particular a Bayer filter, and/or wherein the image sensor comprises a plurality of visible light sensitive sensor areas and a plurality of IR-sensitive sensor areas, the plurality of visible light sensitive sensor areas and the plurality of IR-sensitive sensor areas being arranged in and/or at the image plane. 
     
     
         11 . The eye tracking module of  claim 10 , wherein the image plane defines an optical axis of the image sensor, wherein the image plane is perpendicular to the optical axis and/or parallel to a flat central portion of the IR-waveguide, the central portion including the output aperture, the central portion being arranged close to the image sensor. 
     
     
         12 . The eye tracking module of  claim 1 , wherein the image sensor comprises interleaved visible light sensitive sensor areas and IR-sensitive sensor areas, and/or is implemented as an RGB-IR sensor comprising at least one RGB-IR kernel. 
     
     
         13 . The eye tracking module of  claim 1 , further comprising at least one optical element arranged in the optical path, in particular a receiving aperture for the visible light and/or a lens or even a lens system arranged between the receiving aperture and the image sensor for projecting the visible light onto the image sensor, in particular onto the image plane. 
     
     
         14 . The eye tracking module of  claim 1 , wherein the electronics carrier comprises at least one of an electric interface, in particular a respective data and power interface, and a controller functionally connected with at least one of: the electric interface, the image sensor, and the IR-light source, the controller being configured, using data received from the image sensor, to generate time-correlated images of at least two of the first region of interest, the second region of interest and the third region of interest, in particular to generate time-correlated images pairs comprising a scene image representing the first region of interest and a concatenated eye image representing the second region of interest and the third region, to postprocess the time-correlated images and/or the data received from the image sensor, in particular using a trained neural network, and/or to transmit the time-correlated images and/or the data received from the image sensor via the data interface. 
     
     
         15 . The eye tracking module of  claim 1 , further comprising a housing connected with the electronics carrier and covering at least one of the central portion of the IR-waveguide, the IR-light source, and the image sensor, the housing fitting with a central portion of a support structure of the head-wearable device, the central portion providing and/or being shaped as a nose bridge portion of the head-wearable device. 
     
     
         16 . The eye tracking module of  claim 1 , wherein the IR-waveguide is arranged in the optical path and operable as a plane-parallel plate for the visible light. 
     
     
         17 . The eye tracking module of  claim 1 , wherein the IR-waveguide comprises:
 a flat central portion comprising the output aperture; and   a first leg portion comprising the first input aperture and forming an angle different from 0° or 180° with the flat central portion.   
     
     
         18 . An eye tracking module for complementing a head-wearable device of a user, the eye tracking module comprising:
 an electronics carrier;   an image sensor arranged on the electronics carrier;   an optical path for receiving visible light at the image sensor from a first region of interest; and   an IR-waveguide arranged with respect to the optical path to avoid received visible light being diverted and/or guided by the IR-waveguide, the IR-waveguide comprising a first input aperture for receiving IR-light from a second region of interest which is different to the first region of interest, and an output aperture for directly outputting at least a part of the received IR-light to the image sensor, wherein the IR-waveguide comprises:
 a flat central portion comprising the output aperture; and 
 a first leg portion comprising the first input aperture and forming an angle different from 0° or 180° with the flat central portion. 
   
     
     
         19 . The eye tracking module of  claim 18 , comprising a housing connected with the electronics carrier and covering at least one of the flat central portion of the IR-waveguide, the IR-light source, and the image sensor, the housing including a receiving aperture for the visible light. 
     
     
         20 . A head-wearable device, comprising:
 a support structure comprising a central portion providing and/or being shaped as a nose bridge portion; and   an eye tracking module connected with the central portion, the eye tracking module comprising:   an electronics carrier;   an image sensor arranged on the electronics carrier;   an optical path for receiving visible light at the image sensor from a first region of interest, wherein the first region of interest is related to a field of view of a user when wearing the head-wearable device; and   an IR-waveguide arranged with respect to the optical path such that received visible light avoids being diverted and/or guided by the IR-waveguide, the IR-waveguide comprising a first input aperture for receiving IR-light from a second region of interest which is different to the first region of interest, and an output aperture for outputting at least a part of the received IR-light towards the image sensor, wherein the IR-waveguide comprises:
 a flat central portion comprising the output aperture; and 
 a first leg portion comprising the first inpat aperture and forming an angle different from 0° or 180° with the flat central portion.